Vacuum cleaner power nozzle having selectively introduced secondary airflow for operation on carpeted surfaces

ABSTRACT

A vacuum cleaner power nozzle adjustable for use on low- and high-pile carpets. Vent openings across the front of the nozzle selectively open to introduce a secondary flow of air at the leading side of the roller brush of the nozzle. The secondary flow of air reduces resistance to movement of the power nozzle over high-pile carpet, and is drawn under the rotating roller brush to aid in displacement and removal of particulate from the carpet.

RELATED CASES

This application claims the benefit of U.S. Provisional Patent Application Serial No. 62/388,434, filed Jan. 27, 2016.

BACKGROUND

a. Field of the Invention

The present invention relates generally to vacuum cleaners having powered roller-brush nozzles for collection of dirt and debris from floors and other surfaces, and, more particularly, to a roller brush vacuum cleaner nozzle having a secondary flow of air the is selectively introduced proximate to and in front of the roller brush to reduce resistance to movement over high-pile carpets without reducing the cleaning performance of the nozzle.

b. Related Art

The majority of modern vacuum cleaners include a nozzle assembly (referred to from time-to-time as a “power nozzle”) having a suction intake that is disposed toward the floor surface and a powered roller brush located in or adjacent the intake. The roller brush, which may include a beater bar or other rigid/semi-rigid features agitates and sweeps the carpet or other floor surface to dislodge dust and dirt, so that the particulate material is carried away on the flow of air entering the suction intake and collected in a bag or other container within the machine. The roller brush is powered by an electric motor (e.g., directly via a drive belt). For reasons of efficiency, the roller brush and associated suction opening are generally transverse to the normal forward-reverse direction of movement of the nozzle assembly.

Power nozzles having the general configuration described in the preceding paragraph have been developed to achieve a high degree of efficacy and ease of use on the most commonly encountered types of floor surfaces, such as bare floors and short-pile carpets. However, significant problems have remained in use on carpets having particularly tall and/or thick piles, such as “shag” or “frieze pile” carpets, the latter featuring notably tall and thick piles with tightly twisted yarns.

Conventional power nozzles encountering tall/thick pile carpet of the types noted above generally exhibit a strong tendency to “dig” into the pile, primarily owing to the effect of the suction at the intake opening pulling the body and edges of the nozzle assembly down into the carpet and forcing the roller brush deep into the pile. The resulting resistance can make it exceptionally difficult for an operator to move the nozzle assembly back-and-forth manually. Moreover, as the nozzle assembly digs into the carpet, rotation of the roller brush tends to bog down and flow to suction opening becomes impaired by the surrounding pile so that cleaning performance becomes very poor.

Given its long-standing nature, numerous efforts have been made to address the problem of power nozzles digging into high-pile carpets. The most common approach has been to provide a height adjustment mechanism that raises the entire nozzle assembly on its wheels when tall-pile carpets are encountered. In practice, however, the results have generally been unsatisfactory, due in large part to the tendency to lift the roller brush out of engagement with the carpet and the greatest extent of the pile and thereby defeat its ability to agitate and displace dirt and other particulate. Also, lifting the intake opening to the loose upper ends of the tall pile allows air to enter from the sides of the nozzle, severely impairing the ability of the suction to lift particulate out of and away from the carpet itself.

Other prior efforts have taken the form of various relief openings or mechanisms of one form or another that introduce air into the housing of the nozzle assembly to reduce the amount of suction at the intake opening, but as a group these have again provided very little benefit at the expense greatly reduced cleaning performance.

Accordingly, there exists a need for a vacuum cleaner power nozzle that is capable of operating on a high pile carpet without excessive resistance to movement while maintaining an acceptable level of cleaning efficacy.

SUMMARY OF THE INVENTION

The present invention addresses the problems cited above, and provides a vacuum cleaner power nozzle assembly having a secondary airflow that is introduced proximate and ahead of a roller brush of the assembly, so that the secondary airflow reduces downward suction of the nozzle assembly into a carpet while maintaining airflow over and agitation by the roller brush of the assembly to retain cleaning efficacy of the nozzle assembly.

In a broad aspect, the nozzle assembly comprises (a) a vacuum intake formed on a lower side of the nozzle assembly, (b) a powered roller brush mounted in the intake so as to extend generally transverse to a front-to-back direction of motion of the nozzle assembly, and (c) at least one passage permitting entry of a secondary flow of air to the intake opening on a front side of the roller brush, so that the secondary flow of air reduces downward force exerted by vacuum in the opening and is drawn downwardly and under the roller brush by rotation of the latter so as to aid in dislodging and removing particulate matter from the carpet.

The at least one passage may comprise at least one passage that communicates between the intake opening of the nozzle assembly and an exterior of the nozzle assembly so that the secondary flow of air is drawn from outside the nozzle assembly. The at least one opening may be selectively openable by an operator for use a on/high pile and/or dense nap carpet, and selectively closable by an operator for operation on a short and/or low density nap carpet or bare floor surface.

The at least one opening for the secondary airflow may comprise a plurality of openings at spaced apart locations across a forward end of the nozzle assembly. The nozzle assembly may further comprise a mechanism by which the operator is able to open and close the plurality of openings for entry of the secondary flow therethrough. A mechanism by which the operator selectively opens and closes the plurality of intake openings may comprise a slider plate having a plurality of openings that are selectively positionable in and out of register with cooperating openings formed in a housing of the nozzle assembly.

The conduit supplying the secondary airflow may comprise a discharge through which the secondary flow of air enters the intake forwardly at a constriction proximate the roller brush so that the secondary airflow is drawn downwardly and then rearwardly under the roller brush in response to rotation of the latter. The constriction may comprise a constriction formed between the roller brush and a stationary portion of the housing of the nozzle assembly. The nozzle assembly may further comprise a vacuum intake located in the housing rearwardly of the roller brush that receives the flow of air and particulate matter dislodged and carried by the flow of air passing under the roller brush.

These and other features and advantages of the present invention will be more fully appreciated from a reading of the following detailed description with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an upper perspective view of a power nozzle assembly that in accordance with the present invention includes openings on the front of the assembly to selectively admit a secondary flow of air at the leading edge of the roller brush of the power nozzle;

FIG. 2 is an upper perspective view of the upper housing of the nozzle assembly of FIG. 1, showing the configuration of the secondary airflow openings and a sliding control panel operable to open and close the openings according to carpet conditions;

FIG. 3 is an upper perspective view of the housing of FIG. 2, with the sliding panel and retaining bracket removed to show the arrangement of the secondary openings airflow in greater detail;

FIG. 4 is an upper perspective view of the sliding control panel and retainer of the housing of FIGS. 2-3;

FIG. 5 is a lower perspective view of the power nozzle assembly of FIG. 1, looking from the rear towards the front, showing the relationship of the secondary airflow openings to the roller brush in greater detail;

FIG. 6 is a lower perspective view of the power nozzle assembly of FIG. 1, looking from the front towards the rear, showing the relationship between the roller brush and the suction intake of the nozzle assembly in greater detail;

FIG. 7 is a perspective, cross-sectional view of the power nozzle assembly of FIG. 1, showing the positional relationship and flow path between the roller brush and other components of the assembly; and

FIG. 8 is an elevational, cross-sectional view of the power nozzle assembly of FIG. 1, similar to FIG. 7, showing in greater detail the relationship between the roller brush and the interior of the housing relative to the secondary airflow openings, that ensures the secondary airflow passes downwardly direction and then under the roller brush reduce the downward pulling force and also complement the action of the roller brush when the nozzle assembly is operating in deep pile carpet.

DETAILED DESCRIPTION

FIG. 1 shows a power nozzle assembly 10 in accordance with a preferred embodiment of the present invention. As can be seen, the nozzle assembly includes a body 12 having a housing 14 and base plate 16 that enclose the major working components of the assembly, with a pivoting neck section 18 that connects the nozzle assembly to a tubular member leading to a particulate collection chamber/bag within the vacuum cleaner itself

As will be described in greater detail below, the interior components of the power nozzle include a roller brush that is located in a bottom opening near the front 20 of the body 12 and that is aligned transverse to the main, longitudinal direction of motion of the assembly. In operation, the roller brush acts to agitate the carpet or other floor surface to dislodge dirt and other particulate material, that is then carried away by a suction that is supplied to the nozzle assembly from a blower (not shown) via neck 18 or when suiable conduit, plenum or other form of connection/common entry with the blower. The roller brush is rotated on its axis by a motor, typically electric, acting directly or through a belt or other suitable drive mechanism.

As can be seen with further reference to FIG. 1, a secondary airflow inlet assembly 30 is mounted in the forward side of housing 14, generally proximate the forward edge 20 of the housing and above the leading lower edge 32 of the base plate.

The inlet assembly includes a plurality of openings 34, suitably arranged in a row across the front of and generally parallel the roller brush, through which a regulated amount of air is drawing from outside body 12 into the opening in which the roller brush is housed. As will be described in greater detail below, the secondary airflow is particularly introduced at the forward side of the roller brush so that the flow travels along with rotation of the brush in order to pass under the rush to aid in dislodgement and removal of particulate material. In order to admit a sufficient flow of secondary air, the openings are preferably sized comparatively large in area, for example, a row of six roughly 0.5×0.65 inch (approx. 13×16.5 mm) oval openings when using a nominal 12-inch (300 mm) roller brush shaving an outside diameter of about 2 inches (25 mm) rotated at typical speeds in the illustrated embodiment, It will be understood, however, that various other sizes, shapes and numbers of openings may be used, or single or multiple elongate slots, depending on the required airflow, aesthetics, and other design factors.

Adjustable control over the secondary airflow is provided by a regulator plate 36, that is mounted to the front of housing 14 and that includes openings 38 that cooperate with corresponding openings 40 in the housing to define the secondary airflow passages 34. The regulator plate is retained for lengthwise sliding movement in a track defined between the outer shell of the housing and a surrounding frame 42, with a finger engagement pad 44 on the outer face of the regulator plate facilitating manual movement of the plate. hen in a first position (e.g., to the left in the view of FIG. 1) the openings 38, 40 in the regulator plate and housing respectively are aligned in register so that passages 34 are fully opened to maximize the secondary airflow, for example, as may be needed for operation on a long pile/thick nap carpet. When slid a second position (e.g., to the right in FIG. 1) the opening 38, 40 move out of register with one another so as to close off passages 34 and thereby block the secondary airflow, as may be desirable operation on a bare floor or low-pile carpet. The regulator plate similarly may be slid to intermediate positions so as to partially open/block the secondary airflow passages 34 and thereby adjust the secondary airflow between a maximum and minimum, as may be desirable or suitable for a variety of carpets or other floor surfaces.

As can be seen in FIG. 2 and FIGS. 3-4, the frame 42 that retains the register plate is mounted to the front of the housing in a cooperatingly-shaped channel molding 46 having a channel recess 48 that receives the rearward edge of the frame, with the two pieces suitably being glued or otherwise joined together. As can be seen in FIG. 4, the depending ends of the frame define stops at the ends of the channel for the register plate, with the length of the slider channel being longer than that of the register plate so that a gap 50 is formed at one end or the other to permit lateral sliding movement of the plate as indicated by doubled ended arrow 52. The lower edge of the register plate is in turn slidingly received in a channel formed in a lower frame piece 54 (see FIG. 1) that is mounted along the upper front edge of the base plate 16 of the nozzle assembly.

FIGS. 5-8 illustrate in greater detail the relationship of the secondary airflow inlets with the roller brush and open intake opening of the power nozzle, and the associated flow path down and under the roller brush to the vacuum intake that is located more towards the rear of the nozzle assembly.

As was noted above, and as can be seen in FIG. 5, the inner discharge ends of the secondary airflow openings 34 are located proximate to and generally forwardly of the roller brush 60 of the nozzle assembly. The roller brush, in turn, is located within the suction opening 62 in the bottom of the nozzle assembly, proximate the forward edge 20 thereof. In effect, therefore, the discharge units of the secondary airflow openings 34 are formed in the forward wall of an elongate chamber having the suction opening at the bottom, with a slot 64 formed by a gap between the roller brush and the forward wall of the chamber. Rotational movement of the surface of the roller brush in this area is in a downward and then rearward direction, as indicated by arrow 66 in FIG. 5, dislodging and pushing particulate rearwardly towards the vacuum intake (see FIG. 6). The secondary airflow entering the chamber in front of the roller rush via openings 34 is impinged by the bristles/beater bar or other surface features on the roller brush, and consequently is also drawn in a downward and under direction as indicated by arrow 70 in FIG. 8, in a manner not unlike that of a paddle-wheel. This results in a dual impact on the performance of the power nozzle: First, the downwardly-directed secondary airflow impinges the carpet surface and locally reduces the partial vacuum under the slot opening 64, reducing the down-force at the front of the nozzle assembly and thus relieving the leading edge of the base plate from digging into the carpet and reducing resistance to front-to-back movement of the nozzle assembly on high-pile carpets. Secondly, the downward and rearward path of the secondary airflow augments and complements the agitation and propelling action of the roller brush, further helping to dislodge particulate material and direct it back towards the vacuum intake 68 at the rearward side of the suction opening 62. This combination of effects results in the machine being far easier to push and maneuver in tall/long pile carpet, while at the same time retaining an essentially uncompromised or even enhanced cleaning efficacy.

To help maximize the above effects, the area above the secondary air openings is preferably constrained or restricted to prevent the flow from being drawn in the opposite direction, i.e., back over the top of the roller brush to the vacuum intake. As can be seen in FIG. 8, this is achieved in the illustrated embodiment by locating the roller brush so that the upper, forward part of the brush is positioned in close proximity to the inside surface on the adjoining portion 72 of the housing, so as to minimize or even eliminate the gap 74 between the two in this area. For example, in the illustrated embodiment the gap 74 at the chamber is suitably about 0.1 inch (2 mm) or less, while due to the diverging curvature of the roller brush and front wall the chamber below widens to 0.25 inch (6.5 mm) or more before opening out through the bottom slot. It will be understood that in various embodiments the location of this or other restriction or block to the flow of air is formed or positioned may vary from that of the illustrated embodiment.

It will be understood that the scope of the appended claims should not be limited by particular embodiments set forth herein, but should be construed in a manner consistent with the specification as a whole. 

What is claimed is:
 1. A vacuum cleaner power nozzle assembly, comprising: an intake opening formed on a lower side of said vacuum nozzle assembly; a powered lower brush mounted in said intake opening so as to extend generally transverse to a front-to-back direction of movement of said power nozzle assembly; and at least one selectively openable passage that permits entry of a secondary flow of air into said intake opening on a front side of said roller brush, so that said secondary flow of air reduces down force exerted by a vacuum in said intake opening, and so that said secondary flow of air is drawn downwardly and under said roller brush by rotation of said roller brush so as to aid in dislodging and removing particulate matter from a carpet.
 2. The vacuum cleaner power nozzle assembly of claim 1, wherein said at least one passage that admits entry of said secondary flow of air to said intake opening comprises: at least one passage that communicates between said intake opening of said nozzle assembly and an exterior of said nozzle assembly so that said secondary flow of air is drawn from outside said nozzle assembly by said vacuum at said intake opening.
 3. The vacuum cleaner power nozzle assembly of claim 2, further comprising: a chamber into which said secondary flow of air is introduced from said at least one intake opening, said chamber extending across at least a portion of said front side of said roller brush.
 4. The vacuum cleaner power nozzle assembly of claim 3, wherein said chamber comprises: a flow restriction formed above said at least one intake opening so as to prevent said secondary flow of air from being drawn back over a top of said roller brush by vacuum in said intake opening.
 5. The vacuum cleaner vacuum assembly of claim 4, wherein said flow restriction is formed by a convergence between an upper portion of said roller brush and a forward wall of said chamber. 